1. Field of the Invention
The present invention relates to a tape carrier type semiconductor device, and more particularly, to a tape carrier type semiconductor device called a COF (chip on a flexible printed circuit) comprising a long flexible insulating tape and a plurality of semiconductor devices sequentially arranged on one surface of the tape, each semiconductor device having a wiring pattern and a semiconductor element.
2. Description of Related Art
COFs in the form of pieces are incorporated into a panel of a portable phone, a PDA (personal digital assistance), a notebook PC, a liquid crystal TV or the like. COFs in the form of long tapes have a structure where a plurality of semiconductor elements are sequentially mounted at equal distances on the same surface of a long flexible insulating tape (tape carrier) that has a plurality of predetermined metal wiring patterns thereon.
Examples of a method of mounting the semiconductor elements on the tape carrier include thermocompression bonding by heating a part of each wiring pattern called an inner lead provided on the tape carrier and an electrode of each semiconductor element from a surface of the tape carrier opposite to the wiring pattern and applying a pressure from the surface of the tape carrier opposite to the wiring pattern.
After mounting the semiconductor elements, a resin is injected into the interface between the tape carrier and the semiconductor elements and cured to protect surfaces of the semiconductor elements. Then, a non-defective/defective determination test is conducted by a tester for exclusive use while standing a probe needle in an external output terminal called an outer lead provided on the tape carrier.
By this test, it is determined whether each of COFs (semiconductor devices arranged on the tape carrier) is a non-defective or a defective.
As shown in FIG. 3, for a COF determined to be a non-defective, a hole 8 for indicating that the COF is a non-defective is bored out with a die through the tape carrier outside a predetermined region enclosed by an outline 6 of the COF.
Then, using a specific device, each COF is identified as a non-defective or a defective by the presence or absence of the hole 8. For a defective having no hole 8, a hole 9 is punched out with another die to remove a portion having a semiconductor element 2 at the center, as shown in FIG. 3. Then, the resulting COF in the form of a long tape undergoes a final inspection and is shipped in a reeled state to the user.
After receiving the COF in the form of a long tape, the user die-cuts it with a die sequentially along the outlines 6 into COFs in the form of pieces separate from one another, as shown in FIG. 4.
Since the COFs in the form of pieces into which the COF in the form of a long tape has been die-cut sequentially along the outlines 6 cannot be identified as a non-defective or a defective by the presence or absence of the hole 8 shown in FIG. 3, it is identified as a non-defective or a defective by whether the portion having the semiconductor element 2 at the center is removed or not (as shown in FIG. 4, for a defective, the hole 9 is punched out therein to remove the portion having the semiconductor element 2 at the center, whereas for a non-defective, the hole 9 is not punched out therein). Thereafter, only COFs identified as non-defectives are mounted and put into commercial production.
Examples of a method of identifying an integrated circuit (IC) as a non-defective or a defective include one described in Japanese Unexamined Patent Publication No. 63(1988)-288038.
The following is the gist of a “tape carrier” disclosed in Japanese Unexamined Patent Publication No. 63(1988)-288038.
The disclosed tape carrier is aimed to prevent the erroneous recognition of detection using a photo sensor by forming light-shielding pads on parts of an insulating film whereon there exists no metal wiring pattern and boring a hole in the parts whereon there exists no metal wiring pattern so that the hole penetrates the insulating film.
More specifically, an IC metal pad 8 is provided and a through hole 9a is bored therein. A pad free from errors of detection has a size of 2 mm×2 mm or more in square when the hole has a diameter of 1 mm. Moreover, a hole like 9b may be bored in a part of a wiring pattern. In this case, pads 6 may have a largish size and an electric test may be conducted even after the hole is bored in the pads. In a case where the color of an insulating film 1 is relatively deep, not the whole periphery of the hole but only a part thereof may be covered with a metal.
With the above construction, a detection using a photo sensor can be executed with a high reliability on the basis of the presence or absence of the hole in the carrier tape so that a mistake that a non-detective is removed or a defective is handled as a non-defective is eliminated.
According to the above publication, after an IC is identified as a non-defective or a defective, a hole is bored through the tape carrier outside or inside a region enclosed by an outline of a COF arranged on the tape carrier, and then the COF arranged on the tape carrier is identified as a non-defective or a defective by the presence or absence of the hole.
Meanwhile, the aforementioned COF in the form of a long tape is shipped in a state that the holes 9 are punched out with the die in defectives to remove the portions each having the semiconductor element 2 at the center, as described above. The die is of a size large enough to be allowed for shared use and to be adapted to change to a certain degree in size of the semiconductor element 2.
The COFs in the form of long tapes received by the user are transferred reel to reel to be die-cut with the die sequentially along the outlines 6 into COFs in pieces. At this time, in the case where a COF in the form of a thin tape (generally having a thickness of 40 μm or less) is provided with large holes 9 sequentially punched out therein to remove large portions, deformation could be caused in the tape to make the transfer of the tape unstable and thereby the risk of failure in the die-cutting into pieces could be raised.
Further, once the COF in the form of a long tape is die-cut along the outlines 6 into pieces, each COF in the form of a piece cannot be identified as a non-defective by the presence or absence of the hole 8 shown in FIG. 3.
On the other hand, the “tape carrier” disclosed in Japanese Unexamined Patent Publication No. 63(1988)-288038 where detection is made by a photo sensor needs special devices including the photo sensor.